Introduction to FSD technology for cars

As a leading manufacturer of high performance shock absorbers KONI develops the technical features of all its dampers by following a simple principle: to meet the diverse demands of market applications with sophisticated, and market leading mechanical solutions.

The everlasting problems with vehicle damping

Vehicle damping has always been a compromise between comfort and road-holding. An obvious example is a Formula 1 racing car which offers the best possible road-holding but with minimal comfort. In a personal or sport car one expects to experience the ultimate in comfort, combined with safe road-holding. Minimum damping is required for your comfort whilst strong damping is needed for safe and stable driving. This conflict of goals can not be solved with conventional front & rear dampers. Other damper systems currently available to the market do not offer an adequate solution:

  • Position-dependent shock absorbers will give you extra comfort, as they allow more movement of your car, but as a result the road-holding is inferior. Sudden bumps in the road will still be very unpleasant.

  • Pneumatic and electronic adjustable shock absorbers may improve road-holding in the future. The disadvantage of such complex systems is that they are very expensive and time consuming to set up correctly.

KONl shock absorbers with Frequency Selective Damping (FSD) technology offer the solution. Specifically designed for personal and sport cars, KONI FSD technology combines the ultimate in comfort and road-holding. Being a purely mechanical technology, removes any cost, reliability, or complexity problems which can arise from using electronically controlled suspension components.

KONl FSD high performance dampers are your first choice in solving the everlasting problem with vehicle damping.

FSD principles

In general suspension terms, the conflict between comfort and handling can be split in two different frequency areas:

  • For comfort, with the suspension moving in a high frequency area (± 10 Hz), it is neccessary for low damping forces for the vehicle to remain comfortable.

  • For handling, with the suspension moving in a low frequency area (± 1 Hz), it is neccessary for high damping forces for the vehicle to remain safe and in control.

Conventional dampers are unable to solve the conflict in terms of comfort and handling, however if you are able to create a damper which can change the damping force level in relation to the frequency of the movement, you will be able to solve this conflict.

The KONI FSD technology does just that!

How does it work?

In standard shock absorbers the main damping characteristic is defined by the oil flow going through the piston assembly.

Combining this standard damping characteristic with the FSD feature, KONl added a special valve which is able to control a parallel oil flow next to the one going through the piston. This parallel oil flow is closed by the FSD feature, giving a rise in damping force almost linear to the time that the piston is moving in one direction.

Put simply: the FSD feature is a hydraulic amplifier that delays the build up of pressure. One could say that an extra tuning option has been created in order to get the best possible combination of handling and comfort.

Since it is an integrated part of the hydraulic valve system inside the damper, no additional cables, sensors or any other electronic devices are needed to operate an FSD damper.

In comparison with costly systems which work on the basis of computer technology, complex electronics and sensors, FSD is the simplest and most economic way to significantly improve the ride and driving characteristics of every car.